GE B30 Instruction Manual page 423

CHAPTER 5: SETTINGS GROUPED ELEMENTS
Main path sequence
Figure 5-109: Breaker failure main path sequence
The current supervision elements reset in less than 0.7 of a power cycle for any multiple of pickup current as shown in the
following figure.
Figure 5-110: Breaker failure overcurrent supervision reset time
5
Settings
— This setting is used to select the breaker failure operating mode: single or three pole.
BF1 MODE
— If set to "Yes," the element is initiated if current flowing through the breaker is above the supervision
BF1 USE AMP SUPV
pickup level.
— If set to "Yes," the element is sealed-in if current flowing through the breaker is above the supervision
BF1 USE SEAL-IN
pickup level.
— This setting selects the FlexLogic operand that initiates three-pole tripping of the breaker.
BF1 3-POLE INITIATE
— This setting specifies a pickup delay for the re-trip command. Set this delay longer than the
BF1 RETRIP PICKUP DELAY
possible spurious contact input activation duration due to transients or temporary DC grounds, taking into account the
contact input de-bounce time to avoid re-trip operation for such transients.
— This setting is used to set the phase current initiation and seal-in supervision level. Generally this
BF1 PH AMP SUPV PICKUP
setting detects the lowest expected fault current on the protected breaker. It can be set as low as necessary (lower than
breaker resistor current or lower than load current)—high-set and low-set current supervision guarantee correct operation.
B30 BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-215